The present invention relates to a method and an apparatus for using hazardous waste to form non-hazardous aggregate by thermally induced oxidation.
Many industrial processes produce by-products and waste materials that cannot be legally disposed of without some type of containment or treatment. Efforts in the past to dispose of such materials within containment vessels have proved inadequate since lack of attention to the manufacture of such containment vessels or their deterioration results in leakage or spillage of the hazardous waste. Other means of treating hazardous waste include the injection of such materials into wells, however, such materials may not be immobile within the strata into which they are injected and may find their way into underground aquifers.
In addition to the technical problems associated with such disposal techniques, there remains potential liability for anyone using such facilities. Years after the materials are deposited at the disposal site, claims for liability can be generated based on the knowledge that a party has been responsible for placing hazardous material within an approved waste disposal site only to have the disposal site be unsuccessful in preventing dispersion of the waste. Such problems have generated a search for means of using hazardous waste in a manufacturing process to eliminate its hazardous nature to produce a product suitable for sale to and use by the general public. One of the means attempted has been to oxidize the material by passing it through various types of heaters under oxidizing conditions. One such variation of such a process uses a counter current rotary kiln to induce combustion of the combustible components in the hazardous waste and to aggregate the non-combustible material into a form that could be sold as a commercially valuable and useful product.
Efforts in this particular method of waste use have been partially successful in manufacturing a product that will pass the applicable EPA regulations associated with the disposal of waste. These processes, however, have significant shortcomings. The most significant shortcoming associated with the use of hazardous waste in a rotary kiln or the like is the generation of additional non-combustible material that is not formed into an aggregate and must be disposed of as hazardous waste. Thus, although the amount of the hazardous waste has been significantly reduced by the process, there still remains the problem of disposal of a portion of the treated material as hazardous waste material. In addition, most conventional processes generate large quantities of contaminated scrubber water that must be treated and disposed of.
Therefore, it is one object of the present invention to provide a method and an apparatus for using hazardous waste material as a recyclable material in a manufacturing process such that the only products of such a process are non-hazardous and may be sold for use by the general public without concern as to the nature of the input materials that were processed.
It is another object of the invention to convert hazardous solid materials to a non-hazardous, inert aggregate that may be sold without restriction.
It is another object of the invention to make use of hazardous waste liquids as fuels and fuel supplements in lieu of natural gas or coal in an economical fashion where any solids resulting from the use may be sold to the general public without concern as to the hazardous nature of the input materials.
It is an additional object of the invention to provide a system for the use of hazardous waste materials on a large scale that can be operated economically without significant risk to personnel operating the system. These and other objects of the invention will be more fully disclosed in the present specification or may be apparent from practice of the invention.